package collection;

import java.util.ArrayList;
import java.util.Collection;

public class CollectionDemo3 {
    public static void main(String[] args) {
        Collection c = new ArrayList();
       // c.add(123);//c.add(Integer.valueOf(123));此处自动装箱了
        Point p = new Point(1,2);
        c.add(p);//将p添加到集合c中-------将引用（地址）装到了c中
        System.out.println(c);
        p.setX(100);
        System.out.println(p);
        System.out.println(c);
    }
}
